1. Technology Field
The present invention relates to a key transport method. Particularly, the present invention relates to a method for transporting a key from a buffer memory to an encryption/decryption unit through a bus, and a memory controller and a memory storage apparatus using the same.
2. Description of Related Art
Digital cameras, cell phones, and MP3 players have undergone rapid growth in recent years, so that consumer demands for storage media have also rapidly increased. A rewritable non-volatile memory is one of the most adaptable memories for portable electronic products, for example, mobile phones, personal digital assistants and notebook computes, etc. due to its characteristics such as data non-volatility, low power consumption, small volume, non-mechanical structure, and high read-and-write speed. Thus, in recent years, the flash memory industry has become a major part of the electronic industry. The rewritable non-volatile memories have been broadly applied to personal data storage due to its small volume, large capacity, and high portability. However, the data stored in a rewritable non-volatile memory apparatus may be stolen when the rewritable non-volatile memory apparatus is lost. In order to resolve such problem, an encryption/decryption unit is generally added to the rewritable non-volatile memory apparatus to prevent data from being arbitrarily read or stolen.
Generally, before an encryption/decryption algorithm (for example, an advanced encryption standard (AES) and a data encryption standard (DES), etc.) is used, one to three keys have to be first input. Conventionally, in hardware implementation, all keys are generally written into a register of the encryption/decryption unit altogether. However, in view of a data bus or a side channel, the keys have a risk to be recorded stealthily by a hacker. FIG. 1 is a schematic diagram of key transportation according to a conventional technique. Referring to FIG. 1, before an encryption/decryption unit 1 is used, a key 252a has to be transported from a buffer memory 252 to a key register 1a of the encryption/decryption unit 1. Generally, according to the conventional technique, the key 252a is altogether written into the key register 1a of the encryption/decryption unit 1, so that a content of the key 252a is uninterruptedly appeared on a data bus 401. Therefore, during a period when the key 252a is transported, a hacker can obtain the content of the key by probing the data bus 401 or measuring energy variation or power loss, etc. Therefore, a secure and reliable key transport method is required to be developed.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the present invention. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention, or that any reference forms a part of the common general knowledge in the art.